\frac{r \cdot \sin b}{\cos \left(a + b\right)}r \cdot \left(\sin b \cdot \frac{1}{\cos b \cdot \cos a - \sin b \cdot \sin a}\right)double code(double r, double a, double b) {
return (((double) (r * ((double) sin(b)))) / ((double) cos(((double) (a + b)))));
}
double code(double r, double a, double b) {
return ((double) (r * ((double) (((double) sin(b)) * (1.0 / ((double) (((double) (((double) cos(b)) * ((double) cos(a)))) - ((double) (((double) sin(b)) * ((double) sin(a)))))))))));
}



Bits error versus r



Bits error versus a



Bits error versus b
Results
Initial program Error: 14.9 bits
SimplifiedError: 14.9 bits
rmApplied cos-sumError: 0.3 bits
rmApplied div-invError: 0.4 bits
Final simplificationError: 0.4 bits
herbie shell --seed 2020200
(FPCore (r a b)
:name "rsin A"
:precision binary64
(/ (* r (sin b)) (cos (+ a b))))